1. Field of the Invention
The present invention relates to the technical fields of electro-optical apparatuses utilized in display units for television sets, video cameras, and portable remote terminals, or light modulators for projection display devices or the like. In particular, the present invention relates to the technical field of an electro-optical apparatus which has a construction in which one or a plurality of conductive layers for wiring are laminated between a sealing unit for surrounding an electro-optical material, such as a liquid crystal, and a substrate.
2. Description of Related Art
A typical electro-optical apparatus has a construction in which an electro-optical material, such as a liquid crystal, is held in a region surrounded by a sealing unit between substrates. In order to maintain a gap between the substrates at a predetermined interval, spherical or fibrous particles including beads, glass fibers and the like, so-called xe2x80x9cspacersxe2x80x9d, are mixed in the sealing unit. Pixel electrodes are provided at the inner surface of one substrate of a pair of substrates for driving the electro-optical material, and are connected to a terminal provided in an external region of the sealing unit (i.e., outside the sealed region) via wirings. That is, in the above electro-optical apparatus, a conductive layer includes a single wiring layer between the sealing unit and the substrate.
Additionally, in an electro-optical apparatus having semiconductor switching elements devices on a substrate, since deterioration of image quality occurs due to leakage current caused by the light, a light-shielding layer including metal must be provided between the substrate and the sealing unit to block the incident light from propagating into a semiconductor layer. Hence, wiring formed on the substrate, an insulation layer, and the light-shielding layer are laminated in that order, resulting in the conductive layer including two layers: the wiring layer and the light-shielding layer between the sealing unit and the substrate.
Furthermore, in an electro-optical apparatus in which each pixel has a semiconductor switching element and a driving circuit for driving the semiconductor switching element is provided in an internal region of the sealing unit (i.e., inside the sealed region) as well as for being controlled by a control circuit, one or two layers for wiring and one layer for light-shielding, i.e. three conductive layers in total, may be laminated through insulation layers between the sealing unit and the substrate.
In addition, when the driving circuits are provided outside the sealed region in an electro-optical apparatus, there are cases in which various types of wiring (e.g., scanning lines, data lines, capacitance lines, and the like) are formed between the sealing unit and the substrate by utilizing one or more conductive layers.
As described above, there are electro-optical apparatuses having various constructions in accordance with the driving method, and the location of the driving circuit, and furthermore, in accordance with the number of conductive layers utilized for wiring, light-shielding, electrodes, or the like. In any case, a plurality of lines must be formed from outside the sealed region to the inside of the sealed region, through the conductive wirings between the sealing unit and the substrate.
However, particularly in an electro-optical apparatus having a multiple conductive layers between the sealing unit and the substrate, when both substrates are bonded with the sealing unit, and both substrates are compressed, some portions of the conductive layers are subjected to strong pressure from spacer members contained in the sealing unit. Hence, there are problems such as deformations in the wiring and the light-shielding layer, short-circuits between the wiring and the light-shielding layer due to breakage, short-circuits among the wiring laminated one on top the other through an insulation layer, furthermore resulting in breaking of wirings.
Also, the foregoing problems may be fully anticipated not only specifically in the electro-optical apparatus having the semiconductor switching elements on the substrate, but also in an inner-reflective-type electro-optical apparatus having a construction in which an insulating layer and pixel electrodes are disposed on a reflective layer, composed of Al (aluminum) and the like, disposed on the inner surface of a glass substrate of a pair of glass substrates.
Furthermore, even when various types of wiring from the outside of the sealed region to the inside of the sealed region are formed on only the single conductive layer, and the substrates are compressed, since the conductive layer is subjected to localized pressure from the spacer members, there is the possibility that the wiring will break at that part. In short, in an electro-optical apparatus adopting any of the constructions which form various types of wiring from the outside of the sealed region to the inside of the sealed region utilizing the single layer or multiple layers between the sealing unit and the substrates, breaking of wirings and short-circuit problems caused by such spacer members occur.
The present invention is made in view of the foregoing problems. It is an object thereof to provide an electro-optical apparatus, a method for manufacturing the same, and a projection display device and an electric apparatus having this electro-optical apparatus so as to be able to prevent the wiring formed on one of the substrates holding an electro-optical material from damage by spacer members.
To solve the foregoing problems, the present invention is characterized in that an electro-optical apparatus has an electro-optical material provided in a region surrounded by a sealing unit between a pair of substrates, and a conductive layer laminated on one of the pair of substrates, the sealing unit comprises a part having a spacer member and a part not having the spacer member, and a part of the sealing unit not having the spacer member is provided in a region in which wiring, made of the conductive layer on one of the substrates, faces the sealing unit.
According to the electro-optical apparatus of the present invention, a sealing unit made of a sealant such as a photo-curable or thermosetting resin adhesives is divided into a part having spacer members of a predetermined size, for example, in the shape of beads, or fibers, and a part not having the spacer members. The wiring, made of the conductive layer, is laminated in the region which faces the part not containing spacer members on the substrate. That is, since there is no spacer member in the part of the sealing unit in which the wiring, made of the conductive layer, intersect one another, even though the substrates are compressed, the wirings are not subjected to localized pressure from spacer members. Accordingly, it is possible to prevent breakage due to spacer members. At the same time, since the gap between the substrates is highly accurately controlled by the spacer members contained in the sealing unit, it is very useful in the case of a portable electro-optical apparatus or the like where a mixture of spacer members in an electro-optical material produces deterioration of image quality.
According to one aspect of an electro-optical apparatus of the present invention, the conductive layer includes multiple conductive layers laminated on the substrate through an insulation layer.
According to this aspect, when multiple wiring are formed by using multiple conductive layers insulated to each other by insulation layers, not only the foregoing breakage caused by spacer members can be prevented but also the short circuit of the wiring laminated due to localized pressure caused by spacer members can be prevented.
In addition, using a three-dimensional structure of, for example, a pixel electrode, such as a reflective electrode, lines, such as scanning lines or data lines, a light-shielding layer for an element, such as a TFT (Thin Film Transistor), for switching a pixel electrode on and off or the like, effective utilization for the disposition can be realized in limited space of the substrate by multiple conductive layers. It is advantageous that by adopting a three-dimensional wiring structure, the required widths of the area which the wiring occupy can be reduced, particularly in places where the wiring and the sealing unit intersect.
In another aspect of an electro-optical apparatus of the present invention, a part of the sealing unit not having the spacer members is a shielding unit for shielding an opening through which the electro-optical material is injected.
According to this aspect, since the part not having spacer members mixed therein is the shielding unit for shielding the opening for injecting the electro-optical material, by devising a pattern of wiring, the electro-optical apparatus can be obtained with a single type of sealing material, in accordance with a conventional manufacturing method. Specifically, when the construction is adopted in which the electro-optical material is a liquid crystal and the shielding unit shields the opening for injecting the liquid crystal, since the width of the opening for injecting the liquid crystal is appropriate for various types of wiring required for driving liquid crystal to pass through, it is convenient in practice.
In addition, one of the substrates may be constructed so as to include a plurality of scanning lines and a plurality of data lines, along with a switching element at a pixel location corresponding to each intersection point of these lines, as well as pixel electrodes connected thereto, and the multiple conductive layers include a first conductive layer constituting the wiring for a scanning line driving circuit supplying the scanning lines with scanning signals, and a second conductive layer constituting the wiring for a data line driving circuit supplying the data lines with data signals.
With this construction, since there is no spacer member in a part in which the wiring, made of the first conductive layer, led to the scanning line driving circuit and the wiring, made of the second conductive layer, led to the data line driving circuit are laminated, breakage or short-circuiting in these lines can be prevented. Specifically, when at least one of the data line driving circuit and the scanning line driving circuit are formed inside the sealed region, since there are many cases in which both the first conductive layer and the second conductive layer have laminated layer structures, the structures according to the present invention are useful.
In another aspect of an electro-optical apparatus of the present invention, a part of or the entirety of the conductive layer is a light-shielding layer.
According to this aspect, the conductive layer can be used not only for wiring, but also for wiring and light-shielding, or chiefly for light-shielding for a part (that is, at least a part of a conductive layer among one or more conductive layers). Here, the light-shielding layer is specifically a metal layer made of Al or the like. The conductive layer can function like various types of light-shielding layers, such as a light-shielding layer provided, viewed horizontally, within the sealed region inside the sealant and defining the frames of an image display region for displaying an actual image, as a light-shielding layer (black mask of the color filters, black matrix or the like) light-shielding the gap between numerous pixel electrodes arranged in the image display region or defining an opening region for each pixel, or as a light-shielding layer for preventing deterioration of image quality due to leakage current caused by light in a semiconductor element such as TFT provided for switching-controlling the pixel electrodes. Thus, since the light-shielding layer and the wiring can be formed from the same conductive layer, simplification of the construction of the apparatus and the manufacturing thereof can be achieved.
According to another aspect of an electro-optical apparatus of the present invention, a planarized insulation layer is further provided on the wiring.
According to this aspect, since the apparatus is not of the direct-view type, for example, in the same way as for a reflective light valve for a liquid crystal projector, in a case of a liquid crystal apparatuses in which emphasis is not on increase in the scattering factor of the light but on increase in the reflection factor thereof, it is advantageous that the reflection factor is achieved to be improved by a planarization process. Furthermore, in a region of the substrate facing the sealing unit, normally, uniformity of the height between the substrates along the sealing unit is achieved by the insertion of dummy wiring, and the gap control between the substrates is performed by the spacer members. When the planarization process is performed by CMP (Chemical Machine Polish) processing after the dummy wiring is thus inserted, CMP processing is performed in a preferable manner, and an improvement in flatness is achieved.
In another aspect of an electro-optical apparatus of the present invention, a plurality of pixel electrodes arranged in an internal region of the sealed unit, and a driving circuit connected to the wiring and driving the pixel electrodes are further provided.
According to this aspect, compared to a case in which such a driving circuit is provided in an external region of the sealing unit (outside the sealed region), the total number of wiring intersecting the sealing unit can be reduced. For example, the total number of wiring intersecting the sealing unit is generally far less than the total number of scanning lines and the data lines which lead from the driving circuits to each pixel.
In the aspect of the invention having these driving circuits, this may be constructed so that a plurality of scanning lines and a plurality of data lines, which are connected to the pixel electrodes, are further provided in the internal region of the sealed region, the driving circuit includes a scanning line driving circuit and a data line driving circuit for driving the scanning lines and the data lines, respectively, and the data line driving circuit is provided nearer a part where the wiring intersects the sealing unit than where the scanning line driving circuit is provided.
With such a construction, by wiring provided on a region of the substrate facing a part of the sealing unit not containing spacer members, a signal can be supplied from a control circuit or a signal source to both the scanning line driving circuit and the data line driving circuit provided outside the sealed region. Specifically, in this case, capacitance and delay become greater in accordance with the length of the wiring, made of a conductive layer, such as Al, leading on the substrate. However, by relatively extending the length of the wiring for the scanning line driving circuit driven at a low frequency while relatively shortening the length of the wiring for the data line driving circuit driven at a high frequency, adverse effects caused by such wiring capacitance and delay are barely or not substantially produced, which is advantageous.
Alternatively, in the aspect having this driving circuit, it may be constructed so as to further provide a control circuit in the internal region of the sealed region for controlling the driving circuits.
With such a construction, by wiring provided on a region of the substrate facing a part of the sealing unit not containing spacer members, a signal can be supplied from the signal source outside the sealed region to the control circuit. Specifically, in this case, because the number of wiring from the signal source to the control circuit can be constructed so as to be less than the number of wiring from the control circuit to the driving circuits, it is possible for wiring to be performed even in a small part of the sealing unit not containing spacer members.
A manufacturing method for an electro-optical apparatus of the present invention is characterized in that one substrate having a conductive layer laminated thereon, and the other substrate, are bonded with a sealing unit comprising a part having a spacer member and a part not having a spacer member, the method for manufacturing the electro-optical apparatus comprising a sealing unit forming process of forming a sealing unit provided so that a part of the sealing unit not having the spacer member is provided in a region on the substrate in which the wiring, made of the conductive layer, faces the sealing unit.
According to the method for manufacturing the electro-optical apparatus of the present invention, the sealing unit is divided into a part containing the spacer members and a part not containing spacer members. The sealing unit is formed so that the part of the sealing unit not containing spacer members is provided on the region of the substrate where the wiring, made of the conductive layer, faces the sealing unit. That is, because there is no spacer member in which lines, made of the conductive layer, intersect the sealing unit, when a pair of substrates is bonded by the sealing unit, even though they are compressed, the wiring are not subjected to localized pressure from spacer members. Accordingly, breakage caused by spacer members can be prevented.
In one aspect of a method for manufacturing the electro-optical apparatus of the present invention, the sealing unit forming process includes a process of coating the sealant so that an opening for injection of the electro-optical material is provided in the region in which wiring, made of the conductive layer, faces the sealing unit.
This aspect causes the formed position of the opening part (opening for injecting the electro-optical material) to correspond to that of wiring facing the sealing unit, and solely by devising a pattern of wiring, the electro-optical apparatus of the present invention can be obtained by using a single type of material as the sealing material. Naturally, the opening unit is shielded with the sealant after injection of the electro-optical material.
In one aspect of a method for manufacturing an electro-optical apparatus of the present invention, wiring forming process of forming the wiring from multiple conductive layers is laminated on the substrate through insulation layers before the sealing part forming process.
According to this aspect, after a plurality of wiring are formed using multiple conductive layers by the wiring forming process, when a pair of substrates are bonded by the sealing unit, even though they are compressed, not only the foregoing breakage caused by spacer member can be prevented but also the short circuit of the wiring laminated due to localized pressure caused by spacer members can be prevented.
In order to solve the foregoing problems, an electronic apparatus of the present invention is characterized in that the electronic apparatus includes as a display unit an electro-optical apparatus of the above-described present invention.
According to the electronic apparatus of the present invention, because it is provided with the electro-optical apparatus of the above-described present invention, even though the substrates are compressed, lines are not subjected to localized pressure from spacer members, and so defects of wiring caused by spacer members can be prevented, and improvement in the image display quality, improvement in the apparatus reliability and improvement in the manufacturing yield rate can be achieved.
In one aspect of an electronic apparatus of the present invention, the conductive layer includes multiple conductive layers laminated through insulation layers on the substrate.
According to this aspect, not only the foregoing breakage caused by spacer member can be prevented but also the short circuit of the wiring laminated due to localized pressure caused by spacer members can be prevented.
To solve the foregoing problems, a projection display device of the present invention is characterized in that the projection display device modulates light emitted from a light source by an electro-optical apparatus of the present invention and projects the modulated light onto a screen.
According to the projection display device of the present invention, since light-modulation can be performed by the described above electro-optical apparatus of the present invention, even though the substrates are compressed, the wiring are not subjected to localized pressure from spacer members, and so defects of wiring caused by spacer members can be prevented, and improvement in the apparatus reliability and improvement in the manufacturing yield rate can be achieved.
In one aspect of a projection display device of the present invention, the conductive layer includes multiple conductive layers laminated through insulation layers on the substrate.
According to this aspect, not only the foregoing breakage caused by spacer can be prevented but also the short circuit of the wiring laminated due to localized pressure cuased by spacer members can be prevented.
These operations and other advantages of the present invention will be apparent from the following description of the embodiments.